Propeller-driven watercrafts are generally available as inboard, outboard, and inboard-outboard. Watercrafts with inboard drives (“inboards”) typically have a motor mounted in the watercraft and a fixed-position propeller. Inboards are inherently simpler designs than watercrafts with outboard motor drives (“outboards”) and watercrafts with inboard-outboard drives (“IOs”), or stern drives, so they are relatively lower cost and lower maintenance. Outboards have one or more outboard motors mounted typically at the stern of the watercraft. And IOs have stern drives, which locate the motor inside the boat at the stern. The propeller is part of the stern drive unit behind the transom, which connects to the motor through the transom of the watercraft.
During acceleration from a standstill or nearly a standstill, the bow of outboards and IOs rise up so far that acceleration is reduced, speed is more difficult to control, visibility by the driver is reduced, and loose items, including people, may slide backwards. For inboards this problem is less. While current hydraulic systems can adjust positions of trim tabs and stern drives to make minor changes to the trim angle of the watercraft, current systems do not adjust the trim angle, or bow angle, of the watercraft rapidly enough to address the problem of the raised bow during acceleration. This lack of ability for rapid adjustment has led to the dominance of inboards for boats primarily dedicated to pulling skiers.